This invention relates to cephalosporin antibiotics, and in particular to cephalosporins having a 7.alpha.-hydroxyamino substituent.
U.S. Pat. No. 4,297,488, primarily directed to "7.alpha.-Methoxy Cephalosporins", broadly discloses a literal infinity of cephalosporin antibiotics of the formula ##STR1## wherein R.sup.a represents any acyl group, A represents any organic radical or group, and R.sup.b represents any radical or group replacing hydrogen, and derivatives thereof such as esters, amides and salts. In extensive lists of possible groups which might correspond to R.sup.a, R.sup.b and A in the above formula (still defining virtually infinite compounds) there is noted considerable overlap of possible groups A with present groups R.sup.2 defined below. While for R.sup.a none of the present alpha-(acylamino)acyl groups. ##STR2## defined below, appear to be so listed, for R.sup.b one finds "hydroxiamino" listed among a list of some 100 different functional groups (which corresponds, through a wide variety of optional substituents, to an untold number of specific groups). No such compounds having R.sup.b as hydroxyamino are specifically disclosed or exemplified in this patent.